Physical Sciences Division Research Highlights

Wrapping Up Sensitive Molecules in Nanoparticles

New self-assembling materials protect drug therapies until they reach their target

Like a tough protective bubble, a new class of nanoparticles can envelop and carry sensitive molecules past an array of hazards to their destination.
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Results: Like a tough protective bubble, a new class of tiny particles can envelop and carry certain drugs past an array of hazards to their destination inside the human body. Developed by Pacific Northwest National Laboratory's researchers and their collaborators, these nanoparticles could be an inexpensive way to deliver drug treatments. These particles could protect drugs that break down too quickly inside the body, that cannot mix easily in the blood stream, or that harm healthy tissues on the way to the target.

Why it matters: These particles could provide an inexpensive way to effectively administer certain medications that have a notoriously hard time reaching their target. Called core-shell nanoparticles, the particles break apart slowly, gradually releasing the drugs, which is preferred for certain treatments. In addition, the nanoparticles are easy to store. While some delivery systems are very sensitive to temperature changes and require expensive storage systems, these don't.

Methods: The research team created the particles from long-chain molecules. On one end of each molecule is a chemical group that clusters tightly together around the drug molecule. This action positions the long molecules so the other end, which contains a chemical group that is designed to mix well in water or other aqueous solutions, forms the outer shell. To strengthen the structure, silica particles on the long molecules are crosslinked or polymerized.

Because the chemical groups that form the particle's center are attracted to each other, as are the groups that form the outer shell, the molecules assemble on their own under the right conditions. This simple process can be tailored to develop particles with different properties, which could be beneficial in carrying different molecules through different environments.

What's next: Studies are under way to understand the structure and biocompatibility of these particles. Researchers hope to extend this approach beyond drug therapies to create particles that could be used to carry dyes for sensing and precise medical imaging.

Collaborators: University of New Mexico and Sandia National Laboratories

Funding agency: Pacific Northwest National Laboratory through its Laboratory-Directed Research and Development Program funded this research.

Citation: Huo, Q, J Liu, L-Q Wang, Y Jiang, TN Lambert, and E Fang. 2006. "A New Class of Silica Cross-Linked Micellar Core-Shell Nanoparticles," Journal of the American Chemical Society, 128(19):6447-6453. It is among the most accessed articles in the journal from April to June, 2006.